Intaglio printing from stencil wrapped about cylinder



F b 13 1968 -K. G. LUSHER L v 3 3 4 2 INTAGLIO PRINTING FROM STENCIL WRAPPED ABOUT CYLINDER Original Filed June 8, 1964 I 2 Sheets-Sheet 1 INVENTORS KENNETH .c,. LUSHER BY LOWELL J. WELLS A'ITORNEYS 13, 1963 K. G. LUSHER ETAL INTAGLIO PRINTING FROM STENCIL WRAPPED ABOUT CYLINDER 2 Sheets -Shee1 2 Original Filed June 8, 1964 FIG. 4

THE PRIOR ART FIG. 6

mw w mSH W r w w GJ ATTORNEYS United States Patent 3,368,482 INTAGLIO PRINTING FROM STENCIL WRAPPED ABOUT CYLINDER Kenneth G. Lusher, Perrysburg, and Lowell J. Wells,

Toledo, Ohio, assignors to Owens-Illinois, Inc., a corporation of Ohio Continuation of application Ser. No. 376,291, June 8, 1964. This application Aug. 8, 1966, Ser. No. 579,795

4 Claims. (Cl. 101-153) The present application is a continuation of my earlier application Ser. No. 376,291, filed June 8, 1964.

This invention relates to the art of printing; and more particularly to a novel printing medium for gravure printing or the like; and to a novel method of printing.

The problem Prior methods for decorating irregular surfaces, such as those of glass containers, box board, and others, with heavy ink or colorant applications, are relatively slow and cumbersome. Thus, the prior methods have required flexible transfer mechanisms such as rubber dies in flexographic and letterpress equipment; or etched or molded rubber sheets mounted on steel backing cylinders in the flexible gravure processes such as Uniprint and Colloplas processes.

A disadvantage of a deep cavity on a die surface for holding ink, as in the prior art, is that at high speeds, as of a roller, there is a danger that the ink will be thrown off by centrifugal force or that the gob carried on the surface of the roller will be distorted so that the printed image is similarly distorted, or perhaps smeared. Further, centrifugal forces developed by peripheral speeds of rollers are automatically limiting upon the maximum processing speeds that can be utilized in commercial color-transfer or decorating processes.

A further inherent disadvantage of the prior structures and methods becomes apparent when heavy color applications are attempted to be applied to irregular surfaces, such as cylindrical, glass containers. If a line contact is utilized between the printing medium and the container, there may be an inadequate or spotty ink transfer. When attempts are made to improve the ink transfer by increasing the pressure between the printing medium and the article to be printed, smearing and distortion of the engraved printing surface of the printing medium will occur.

Further, in the prior art, it has been the usual custom, when using an engraved printing surface, to apply ink to the exterior as by a transfer roller and then move the loaded printing medium into contact with the article to be printed.

Further, in the prior art, it is known that high forces are involved in drawing or lifting the ink or dye from a type plate or roll surface onto the material to be imprinted.

Still further, it is known that prior printing processes have required the use of transfer rollers or equivalent means for inking the printing surface or element.

In view of the foregoing, it will therefore be understood that a substantial advancement to the art would be provided by a novel printing medium and method of printing.

It is accordingly an important object to provide a printing medium such as a roller having a surface capable of transferring heavy applications of heavy-bodied printing colorant in a non-smearing and high speed manher.

A further object is to provide apparatus and method for the uniform printing of uneven surfaces such as the surfaces of glass containers, without smearing, and over a large contact area.

A further object is to provide a printing roller where- "ice in ink can be applied from the inside-out, through pores of the roller, for high speed, economical operation along with large contact area over irregular surfaces.

Another object is to provide a printing system wherein ink is actually forced by contact between an article being printed and the surface being printed upon, from the former, onto the latter.

Another object is to provide a printing system wherein force means is provided within a printing roller to transfer heavy applications of ink or colorant to an article being printed with very light contact between the printing medium and the article being printed. A further object is to provide novel use of transfer screen printing media and a method of high speed printing utilizing such media in a manner not heretofore known.

Another object is to provide a novel printing system wherein ink can be forceably transferred between a printing medium and an article being printed with light contacting force between the two.

Another object is to provide a printing system wherein little pressure is required to transfer ink or an ink image from a printing surface to a print-receiving medium, and wherein the transfer is effected by a hydraulic force reaction or fluid force reaction.

Another object is to provide a system of printing without use of doctor blades or transfer rollers, for inking the printing surface or element.

Another important object of the present invention is to provide a printing system and method for printing, particularly adapted for the transfer of heavy applications of printing vehicle such as ink, paint, or other colorant, from a resilient printing medium utilizing a screen transfer mechanism on a surface thereof.

Other objects of the invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

FIGURE 1 is a perspective view of a printing roller embodying the principles of the present invention;

FIGURE 2 is a transverse sectional view taken along the line 22 of FIGURE 1;

FIGURE 3 is a transverse sectional view similar to FIGURE 2, but of another embodiment of the invention;

FIGURE 4 is a side elevational view illustrating the principles of the present invention;

FIGURE 5 is a transverse sectional view taken along the line 55 of FIGURE 4;

FIGURE 6 is a perspective view illustrating the prior art;

FIGURE 7 is a transverse sectional view of another embodiment of the invention, and illustrating external force means and internal force means, as well, for transferring ink between a printing roller of invention, and articles being printed; and

FIGURE 8 is a transverse sectional view illustrating the application of electrostatic force as an ink transfer assisting means within the scope of the invention.

It is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

Perspective view Essentially the invention encompasses a resilient roller as a backing member for a decorating screen, such as a silk screen or a transfer screen made of stainless steel wire. The screen retains heavy quantities of ink against smearing and displacement as by centrifugal force or contact between the surface of the roller and the article being printed. Further, the resilient backing of the roller provides an extended zone of conformance to an article being printed, rendering advantages as will become apparent. Further, the resilient backing, when made in the extended scope of invention in the form of a porous member, acts as a sponge to first absorb, and then force out or expel or exude the ink through the overlying transfer screen. This is a novel approach to printing and the advantages thereof will be made evident as this description progresses.

Further, electrostatic forces can be used advantageously as an assist in the system and method of the present invention; this, by the fact that a steel transfer screen can be used to charge the ink it carries, to one polarity.

The embodiment of FIGURES 1 and 2 As shown in FIGURE 1, a printing roller in accordance with the invention is designated 10. This is supported on a steel shaft 12. A printing image 14 is formed on the surface of the roller 10, and as will become apparent, is adapted to be transferred in heavy ink applications to an article to be printed upon, by the roller.

As shown in FIGURE 2, the shaft 12 is covered with a heavy layer 16, of rubber or analogous elastomeric material. Suitably, rubber having a durometer hardness in the range of about 25 to 60 can be utilized. However, in a preferred aspect of the invention, a rubber hardness in the range of about 30 to 45 durometer will be utilized. This rather substantial body of rubber 16 provides resilience for a substantial contact area between the surface 18 of the roller and the surface 20 of an article 21 being printed. In accordance with the invention, the surface 20 of the article 21 being printed, can have substantial irregularities therein, and yet there will be perfect ink transfer from the surface 18 of the roller of the invention, to the surface 20. This is brought about by the resilient nature of the heavy elastomeric layer 16.

The transfer screen Overlying the resilient core 16 is a transfer screen 22. This may be a silk screen or in some instances is preferably a stainless steel decorating screen, adhered on and around the periphery of the resilient layer 16.

To prepare an image surface 14 on the decorating screen 22, the steps enumerated below are followed:

(1) Coat a decorating screen 22 with a photosensitive emulsion and expose for proper imagery; and

(2) Then wrap the completed screen tightly around the elastic roller 16, and butt the ends together, using suitable adhesive.

The ink feed mechanism of FIGURE 2 As shown in this figure, the roller 10 is supported in space for rotation, a proximate distance above the bottom of a container 26. A body 28 of ink is maintained within the container 26, and the periphery of the roller 10 dips continuously into the ink so that the printing image surface 14 becomes filled with ink.

A doctor blade 30 or squeegee is adjustably mounted adjacent to the periphery 18 of roller 10. This is set to wipe the surface 18. Thus, excess ink is removed from the roller 10 and the non-printing areas are wiped clean, leaving the image surface 14 loaded.

Operation shown, for rotation at the same peripheral speed as that 4 of roller 10, and in a common direction therewith. Instead of using the container 26, shown, the roller 10 may suitably have ink pumped and spread over its surface just prior to engagement by the blade 30.

It will be understood that the image is carried in t e open mesh 14, FIGURE 1, and is thus backed up by the rubber roll 16. It thus can be transferred directly to the article 21. The rubber when compressed against the printing surface, conforms to that surface, enabling a large area to be printed with a relatively large amount of ink. This is more fully brought out by reference to FIGURES 4 and 5.

Before discussing those figures, however, it is pertinent to point out that a modification can be made to the structure of FIGURES 1 and 2. This is shown in FIGURE 3.

The sponge roll embodiment As shown in FIGURE 3, the heavy rubber roll is designated 32. This is designated differently from the solid rubber roll 16 of FIGURE 2, because it is made of sponge-like or porous material. This would preferably comprise sponge rubber; but the extended scope of invention would include polyurethane foam, and analogous materials.

A feature of this modification is that a squeeze roll 34, shown as rubber, but also suitably made of steel, is submerged for rotation beneath the surface of the ink body 28 in container 26. This is shown as being in compressed engagement against the periphery 18 of roll 32. This produces a squeezing action on the roll 32. Thus it compresses the sponge material 32 to force out air, beneath the surface of the liquid 28; and then releases the material 32 so that the sponge can take up large quantities of ink.

A doctor blade 30 or scraper is utilized similarly to FIGURE 2.

Illustration 0) the large Contact area As shown in FIGURE 5, the roll 16 or 32 is contacting the article 21, being printed, over a contact area 36. It will be noted that this is substantially greater than a line of contact.

For exemplary discussion, diamond shapes 38, FIG- URES 4 and 5, of recessed configuration, have been shown as being formed into the surface of the container 21. By reference to FIGURE 5, it will be noted that the contact area 36 fully embraces such surface irregularities 38. Thus, the printing roller 16, 32 conforms to the diamond recess 38 and prints down into it. This would be impossible with line contact along the periphery of the article 21. 7

Though a diamond recessed area 38 has been shown in the surface of article 21, this can well take other forms. Thus, it might be a peripherally-extending groove 40, as shown in FIGURE 4. Ridges and others will become apparent to the reader as these are presently Widely used on soft drink bottles to add character to the bottled beverage.

Continuing to refer to FIGURE 4, note the axially extending contact area 48. Note that this contact area 48 extends well onto the neck 44 of container 21, over the shoulder 46. This would be impossible with line contact printing media, as will be evident to those skilled in the art.

Accordingly, by the present invention, the entire length of the decorating area 48 is covered by one pass of the roller of invention.

The prior art exemplified To illustrate the advance to the art provided by the present invention, refer now to FIGURE 6.

As there shown, the useable printing area 48 of the bottle is the same as the area 48 of FIGURE 4. However, note that two separate printing elements are required for full decoration of only part of this area. Thus, the left hand element 50 covers the area 52. The right hand elemeat 54 is required to cover the remaining area 56. Thus, together, the elements 50 and 54 cover the total area 57, which will be noted to be less than the total decorating area 48, because the shoulder 46 cannot be traversed by a rigid printing element.

This double printing medium requirement is brought about by the line contact and non-conforming nature of the relatively rigid plate printing elements 50 and 54. These are of course analogous to the relatively hard-surfaced printing rollers of the prior art with ink-carrying indentations formed in the surface thereof by suitable means.

A further distinction is noted over the prior art. Thus, the diamond recess 38, the groove 40, and the over-theshoulder lap printing are all effected by the present invention, and in a single pass. Note the hard-surfaced printing media 50 and 54 of the prior art would not provide indentation printing; nor would the over-the-shoulder "reach provided by the roller of FIGURE 4 be produced.

An advantage of the transfer screen In brief review, it will .be understood that several advantages accrue in the present invention from the combination of the resilient backing and the transfer or decorating screen 22 carried on the periphery thereof.

Thus, the transfer screen acts as a grasping or holding or retaining medium, or a retainer for large quantities of ink at a printing situs. This keeps the ink from moving. Stated otherwise, this immobilizes the ink against flow.

This combination is advantageous as follows:

(a) It holds large quantities of ink for transfer at the instant transfer point in space;

(b) It prevents the load of ink from smearing, yet releases it easily and accurately by the back-up pressure exerted by the elastomeric backing roll, thus crisply defining the printed image; and

(c) It resists centrifugal force throw-off. Thus, the ink is held against displacement by both centrifugal force and smearing forces when the large contact area is effected. It will be understood that the resistance against centrifugal force contributes significantly to high speed operation by the present invention.

The internal ink feed aspect Refer to FIGURE 7 for this discussion.

As there shown, the support shaft for the roller instead of being small and solid, as is the shaft 12 of FIGURES 1-3, is an enlarged, annular, drum-like shell 58. This is provided with substantial openings or perforations 60.

The activating medium in this embodiment is a relatively heavy or thick, annular layer 62 of cellular material. This has pores 61 extending from the interior to the exterior, so that ink will move through it by capillary action and under force to be developed.

On the periphery of the annular body 62, is a transfer screen 22, carrying an outer image layer.

A conduit 88 feeds ink from an appropriate supply in metered amounts to the interior of the drum 58. The ink passes through the openings 60 and into the porous mateiral 62 to be travelled to and through the pattern carried by the transfer screen 22, and onto the surface of an article 64; being printed.

There are actually two aspects to this embodiment of the invention, as regards contact with the article being printed. These include an external force aspect and an internal force aspect. In the external force aspect, there is printing contact between the printing medium and the article being printed. In the internal force aspect, there can be the lightest contact. Thus, the broad scope of the invention encompasses from very substantial amounts of contact and pressures of contact to substantially zero contact pressure.

The external force aspect This is illustrated by reference to the article 64 being printed, as shown in FIGURE 7. Thus, there is an actual forced engagement between the outer surface or periphery 66 of roller medium 62 and the article 64. This causes the sufrace of the printing roller to distort or dish or conform or embracingly contact the article being printed 64. The contact, as shown, has spread over a substantial area 68. This is the same type of embracing contact that was described relative to FIGURES 4 and 5. Thus, indentations or elevations can be readily printed by this forced contacting aspect.

In additoin to this aspect, there is also a lightly contacting aspect. This aspect also is shown in FIGURE 7 and, as a means of assisting the ink to travel through the porous layer 62, an internal squeeze roller 70 is utilized. This is suitably a soft, resilient material such as rubber or elastomeric substance and bears against the inside of the drum 58 and presses into or through the apertures 60 thereof. This compresses the annular, porous body 62. The effect is to push the ink through the porous layer 62, and also expel it from the surface of the screen 22 onto the article 72 being printed.

The lightest contact between the surface of the printing roller and the article being printed 72 is therefore used in this aspect of the invention. Practically no force is necessary between the printing medium and the article being printed, to transfer the ink. The force is developed within the printing medium itself and is imposed upon the ink in a fluid pressure-type of action. Thus the ink is forced to flow from the printing roller to the article being printed.

It is known that a substantial force is usually required to transfer ink from a printing roller to an article to be printed. Therefore, a unique aspect of the present invention arises in that the heaviest of ink transfers can be effected, even with the highest viscosity materials, without smearing and without loss by centrifugal force in the case of high speed rotation of the printing roller as in a high speed printing operation.

The force aspect developed further Within the extended scope of invention, a radially outward assist force can be utilized. Thus, as shown in FIG- URE 8, an electrostatic force can be used to supplement or assist the reslient force developed in or by the porous sponge layer 62. It is to be understood, of course, that the resiliently generated force is the principal moving factor within the scope of the present invention and is clearly distinguishable from an electrostatic assist force.

In FIGURE 8, a roller medium 62 of the same nature as that used in FIGURE 7 is employed. This may be used either with or without the internal compression roller 70 described relative to FIGURE 7. Thus the component parts comprise a perforated support drum 58 carrying a porous, spongy layer 62. In accordance with this aspect of the invention, this porous sponge is used for moving in-k from the interior outwardly.

In this aspect of the invention, electrostatic force means may be used to assist the ink in moving between the printing medium and the article being printed.

On the exterior of the porous layer 62 is placed a steel transfer screen 22. A negative electrode member 74 charges the screen 22 and the ink carried thereby to one polarity. A positive electrode memberfl76 charges the surface of the article 78 being printed to opposite polarity. Thus, a printing assist can be provided.

In this aspect of the invention, the article being printed is suitably cradled on rollers 80 for rotation at a peripheral speed synchronized with the peripheral speed of the printing member 62.

In this aspect of the invention, a modification is envisaged. Thus, since the screen 22 is externally carried and receives a charge from an external electrode 74, the

7 printing cylinder 62 can well be of a solid nature illustrated relative to FIGURES 1-3, as distinguished from annular. This would use external ink application, of

course.

On the other hand, if the cellular layer 62 be filled with chargeable particles 82 and be provided with pores 61 so that the ink can move through the thickness thereof from the interior, an electron source 84 can be positioned within the cylinder to develop an assist force. The surface of the article to be printed would still be oppositely charged as by unit 76, previously discussed.

The foregoing various aspects of the invention have been developed in detail to substantiate the broad principle of the invention that a screen transfer mechanism can be carried on the exterior of a resilient body and through the medium of said resilient body, a force can be imposed upon a mass of colorant to transfer that mass of colorant from the image of the screen to an article to be printed by any one of the following ways:

(1) Force developed by contact between the printing medium and the article to be printed, giving a substantial contact area to cover irregularities and the like.

(2) Very light contact with force being developed from within the resilient printing member to expel the ink radially outwardly from the surface into printed relationship upon an article being printed.

(3) An electrostatic assist force so that there need be only the lightest contact between the printing medium and the surface to be printed. In this aspect of the invention, it is of course to be understood that irregularities in the surface of the article to be printed will also be covered.

In its broadest aspect, the invention can comprise the following elements:

A resilient or elastomeric backing body having a surface, and with such surface carrying a transfer screen.

The previous discussion has related to a printing image carried upon a convex surface, and to the transfer of the image from such convex surface onto a convex surface of an article to be printed. Specifically, cylinder-like containers have been disclosed. However, within the extended scope of invention, it is to be understood that the transfer can be to a flat surface. It is also to be understood that a fiat printing image, produced as by mounting a silk screen on a fiat block of rubber could be utilized.

The principles of the present invention are to be construed as applicable for use with fluent printing media; this includes both fluids and powders.

What is claimed is:

1. In apparatus for printing, a non-porous elastomeric body having an external surface, a decorating screen, means securing said decorating screen in intimate contact onto said surface, said decorating screen having a printing image on the external surface thereof, and means for externally applying ink to said image.

2. The invention of claim 1, wherein the printing image is carried in a material coated on said screen.

3. In apparatus for printing, a non-porous elastomeric body having an external surface, said body containing electrically chargeable particles, at decorating screen, means securing said decorating screen in intimate contact onto said external surface, said decorating screen carrying a printing image on the external surface thereof, means for applying a printable colorant material externally to said image, and electrostatic means connected to charge said chargeable particles and an article to be printed, to expel colorant from said image onto the article.

4. The invention of claim 3 wherein the printing image is carried in a material coated on said screen.

References Cited UNITED STATES PATENTS 2,082,115 6/1937 Mershon 101--1l6 2,318,465 5/1943 Chollar 101-327 X 2,333,800 11/1943 Lewis et a1. 29132 2,586,047 2/1952 Huebner 101116 2,590,321 3/1952 Huebner 101116 2,663,257 12/1953 Dudis 101327 2,691,343 10/1954 Huebner 101116 2,763,208 9/1956 Rockoff et a1. 101327 X 2,779,270 1/1957 Hill 101129 2,906,201 9/1959 Blair 101116 3,031,956 5/1962 Worth 101-1l9 3,152,541 10/1964 Carlsen 101125 3,168,036 2/1965 Elsasser 101129 3,172,356 3/1965 Vosburg 101125 ROBERT E. PULFREY, Primary Examiner.

DAVID KLEIN, Examiner.

N. A. HUMPHRIES, W. F. MCCARTHY, E. S. BURR,

Assistant Examiners. 

1. IN APPARATUS FOR PRINTING, A NON-POROUS ELASTOMERIC BODY HAVING AN EXTERNAL SURFACE, A DECORATING SCREEN, MEANS SECURING SAID DECORATING SCREEN IN INTIMATE CONTACT ONTO SAID SURFACE, SAID DECORATING SCREEN HAVING A PRINTING IMAGE ON THE EXTERNAL SURFACE THEREOF, AND MEANS FOR EXTERNALLY APPLYING INK TO SAID IMAGE. 